refactor(i18n): split locale files into per-namespace modules (Phase K) (#688)

Each src/locales/<lang>.ts (~1800 LOC) becomes a folder src/locales/<lang>/
with one module per i18n namespace (44 each) plus an index.ts barrel that
reassembles <lang>Translation in the original key order.

Mechanical, script-driven split with a JSON round-trip check: every
locale object is byte-identical to its pre-split form. i18n.ts is
unchanged — './locales/<lang>' now resolves to the folder index.

The per-namespace settings.ts files land ~440-460 LOC; a single i18n
namespace is the natural, non-arbitrary split unit for a flat string
table, so they are intentionally left whole.

src/locales/de/player.ts

@@ -0,0 +1,56 @@
+export const player = {
+  regionLabel: 'Musikplayer',
+  openFullscreen: 'Vollbild-Player öffnen',
+  fullscreen: 'Vollbild-Player',
+  closeFullscreen: 'Vollbild schließen',
+  closeTooltip: 'Schließen (Esc)',
+  noTitle: 'Kein Titel',
+  stop: 'Stop',
+  prev: 'Vorheriger Titel',
+  play: 'Play',
+  pause: 'Pause',
+  previewActive: 'Vorschau läuft',
+  previewLabel: 'Vorschau',
+  delayModalTitle: 'Timer',
+  delayPauseSection: 'Pause nach',
+  delayStartSection: 'Start nach',
+  delayPreviewPause: 'Pause um',
+  delayPreviewStart: 'Start um',
+  delaySchedulePause: 'Pause planen',
+  delayScheduleStart: 'Start planen',
+  delayCancelPause: 'Pause-Timer abbrechen',
+  delayCancelStart: 'Start-Timer abbrechen',
+  delayInactivePause: 'Nur während der Wiedergabe verfügbar.',
+  delayInactiveStart: 'Nur in Pause mit geladenem Titel oder Radio.',
+  delayCustomMinutes: 'Eigene Dauer (Minuten)',
+  delayCustomPlaceholder: 'z. B. 2,5',
+  closeDelayModal: 'Schließen',
+  delayIn: 'in',
+  delayFmtSec: '{{n}} s',
+  delayFmtMin: '{{n}} Min',
+  delayFmtHr: '{{n}} Std',
+  delayCancel: 'Abbrechen',
+  delayApply: 'Übernehmen',
+  next: 'Nächster Titel',
+  repeat: 'Wiederholen',
+  repeatOff: 'Aus',
+  repeatAll: 'Alle',
+  repeatOne: 'Einen',
+  progress: 'Songfortschritt',
+  volume: 'Lautstärke',
+  toggleQueue: 'Warteschlange umschalten',
+  collapseQueueResize: 'Warteschlange einklappen, Breite ändern',
+  moreOptions: 'Weitere Optionen',
+  equalizer: 'Equalizer',
+  miniPlayer: 'Mini-Player',
+  lyrics: 'Lyrics',
+  fsLyricsToggle: 'Lyrics im Vollbild',
+  lyricsLoading: 'Lyrics werden geladen…',
+  lyricsNotFound: 'Keine Lyrics für diesen Titel gefunden',
+  lyricsSourceServer: 'Quelle: Server',
+  lyricsSourceLrclib: 'Quelle: LRCLIB',
+  lyricsSourceNetease: 'Quelle: Netease',
+  lyricsSourceLyricsplus: 'Quelle: YouLyPlus',
+  showDuration: 'Dauer anzeigen',
+  showRemainingTime: 'Verbleibende Zeit anzeigen',
+};